The present disclosure relates to an apparatus and method of detecting a temperature through a pyrometer in a non-contact manner, and an apparatus for processing a substrate using the apparatus, and more particularly, to an apparatus and method of detecting a temperature, which precisely measures a temperature without any effect by humidity, and an apparatus for processing a substrate using the same.
In a heat treatment apparatus which performs a heat treatment process with respect to a substrate, heat is supplied to a silicon substrate using a heating lamp such as a halogen lamp, and a temperature of the substrate is calculated through an optical probe, and the calculated temperature of the substrate is fed back to a heating controller so as to control the heating lamp.
FIG. 1 is a schematic view illustrating a low temperature heat treatment apparatus. As illustrated in FIG. 1, in a state in which a substrate 20 is installed at an edge ring 30 in a process chamber 10, a heat treatment is carried out by a plurality of heating lamps 61, and a temperature of the substrate 20 is measured by a long wavelength band measuring pyrometer 40 in a non-contact manner. Hereinafter, the pyrometer means a device which measures radiant energy having a long wavelength of approximately 5 μm to approximately 15 μm and converts it into a temperature, thereby calculating the temperature.
Therefore, the pyrometer 40 may concentrate the radiant energy radiated from the substrate 20 and having the long wavelength of approximately 5 μm to approximately 15 μm and a low temperature of approximately 600° C. or less through a lens 41 and then may calculate the temperature of the substrate in the non-contact manner, based on blackbody radiation temperature relationship. The temperature calculated by the pyrometer 40 is fed back to a heating part 60 through a heating controller 50 so as to control the temperature with respect to the plurality of heating lamps 61.
Meanwhile, the long wavelength of approximately 5 μm to approximately 15 μm generally has a property of being absorbed by moisture (H2O). Therefore, if moisture of 100% is present at a light wavelength transmission area, a light wavelength of approximately 5 μm to approximately 7 μm is hardly transmitted, as illustrated in FIG. 2.
Therefore, the long wavelength radiated from the heating lamp 61 is input to the long wavelength measuring pyrometer through an inside of the process chamber 10, and a transmittance of the long wavelength input to the pyrometer is changed by the moisture (H2O) present at the light transmission area.
For example, if moisture (H2O) of 30% is present at the long wavelength transmission area, a transmittance of the light wavelength is 90%, and if moisture (H2O) of 50% is present, a transmittance thereof is 60%, and if moisture (H2O) of 70% is present, the light wavelength has a transmittance of less than 10%.
Therefore, the temperature measured by the pyrometer is changed according to the moisture (H2O) present at the light transmission area. That is, an intensity value of the long wavelength radiant energy input to the pyrometer is changed due to a change in the long wavelength transmittance caused by a difference in the moisture (H2O), and thus an error occurs in a converted temperature value of the pyrometer. Further, a pyrometer having a large diameter may be used in order to complement a low transmittance and receive a large quantity of light. However, in this case, since a size of the pyrometer becomes larger, increase of cost and difficulty in installation occurs, and also miniaturization of equipment is interrupted. That is, on the basis of a wavelength band of approximately 5 μm to approximately 15 μm, the quantity of light in a wavelength band of approximately 7 μm to approximately 15 μm is reduced to 60%, and thus a size of a pyrometer receiving only a wavelength band of approximately 7 μm to approximately 15 μm should be greater 1.7 times that of a pyrometer receiving the wavelength band of approximately 5 μm to approximately 15 μm.